稻鳅共生种养模式试验研究

[目的]稻鳅共生是典型的稻田综合利用模式,符合生态农业发展方向。通过对稻鳅共生生态系统的生理生态学机制开展试验研究,为进一步推广稻鳅共生种养模式提供科学依据。[方法]采用田间试验方法,以水稻单作为对照,研究了不同泥鳅养殖密度下的稻鳅共生对水稻农艺性状、土壤理化性质、水稻产量构成的影响,并对稻鳅共生种养模式进行了经济效益分析。[结果]与对照处理相比,水稻长势在株高、有效分蘖率、根长等方面有一定提高。养殖田水稻株高增高了3%,有效分蘖率提高了8%~11%,根长提高了8.8%~31.3%。在土壤理化性质方面,与对照相比,土壤容重降低了7.1%~21.2%,孔隙度增加了4.1%~14.7%。实验前后养殖田内土壤有机质增加了3.5%~26.5%,对照田降低了2.5%~5.8%。土壤肥力(氮、磷、钾)减少,但减少幅度小于对照处理。稻鳅共生种养模式下水稻产量提高了5%~25%,同时稻田增收泥鳅1 725~3 375kg/hm2,净收入为1.836 0万~2.307 0万元/hm2,经济效益提高了3.65~4.84倍。稻鳅共生种养模式中泥鳅的养殖密度为30万尾/hm2时稻田的生态效益和经济效益最佳。[结论]稻鳅共生有效改善了土壤理化性质,促进了水稻的生长,提高了稻田产量和产值。     

资源依赖、制度安排与区域创新能力 —基于空间杜宾模型

区域创新能力提升是我国加快建设创新型国家、实现高质量发展的现实需求。 本文通过构建涵盖资源依赖、制度安排与区域创新能力的理论模型分析其内在关系并提出假 说，运用2000-2016年全国30个省（区、市）的面板数据与空间杜宾模型，检验三者之间的影 响及空间溢出效应。研究结果表明：（1）资源依赖程度越高，越不利于本地区创新能力提升；（2）有效率的制度安排对区域创新能力有正向促进作用；（3）从空间溢出效应来看，本地区 资源依赖程度越高，越抑制周边地区区域创新能力提升，有效的制度安排能助推周边地区创新能力提高。     

Analytical approximations of local‐Heston volatility model and error analysis

This paper studies the expansion of an option price (with bounded Lipschitz payoff) in a stochastic volatility model including a local volatility component. The stochastic volatility is a square root process, which is widely used for modeling the behavior of the variance process (Heston model). The local volatility part is of general form, requiring only appropriate growth and boundedness assumptions. We rigorously establish tight error estimates of our expansions, using Malliavin calculus. The error analysis, which requires a careful treatment because of the lack of weak differentiability of the model, is interesting on its own. Moreover, in the particular case of call–put options, we also provide expansions of the Black–Scholes implied volatility that allow to obtain very simple formulas that are fast to compute compared to the Monte Carlo approach and maintain a very competitive accuracy.     

Sensory Aspects of Retailing: Theoretical and Practical Implications

Sensory elements are an important aspect of both offline and online retail stores and can non-consciously influence consumer judgments and purchase behavior. In offline settings, ambient factors like scent, lighting, and music have been shown to influence customers’ shopping experiences and their buying behaviors. For online retail outlets, sensory factors related to color, display patterns, and layouts can have significant effects on consumer behavior. Sensory elements have strong managerial relevance since they can non-consciously influence behaviors and because they are relatively easy to change; for example, it requires minimal effort to change the lighting or the music at a physical retail store or the display pattern for an online store. The eight papers in this special issue address theoretical and practical issues related to how different sensory elements can strongly influence retail practices. These papers focus on underexplored topic areas and also on emerging technologies, which stimulate thoughts for further research in these areas.     

系统性金融风险的历史考察与防范对策

深入学习习近平在中国共产党第十九次全国代表大会上的报告，在考察20世纪以来的12次金融危机的基础上，对系统性金融风险发生的根源进行了研究，并结合我国当前系统性金融风险面临的形势，提出了防范系统性金融风险的对策建议。研究表明，将过去100多年引发金融危机的系统性金融风险的根源与我国当前的金融形势进行比较分析，可以发现我国面临的系统性金融风险形势十分严峻，必须在党的领导下，采取打击金融腐败、适当收紧货币政策、完善金融监管体系、维护币值稳定、加强金融科技监管等相关政策来防止系统金融风险的发生。     

Examining artificial intelligence (AI) technologies in marketing via a global lens: Current trends and future research opportunities

Artificial intelligence (AI) has captured substantial interest from a wide array of marketing scholars in recent years. Our research contributes to this emerging domain by examining AI technologies in marketing via a global lens. Specifically, our lens focuses on three levels of analysis: country, company, and consumer. Our country-level analysis emphasizes the heterogeneity in economic inequality across countries due to the considerable economic resources necessary for AI adoption. Our company-level analysis focuses on glocalization because while the hardware that underlies these technologies may be global in nature, their application necessitates adaptation to local cultures. Our consumer-level analysis examines consumer ethics and privacy concerns, as AI technologies often collect, store and process a cornucopia of personal data across our globe. Through the prism of these three lenses, we focus on two important dimensions of AI technologies in marketing: (1) human–machine interaction and (2) automated analysis of text, audio, images, and video. We then explore the interaction between these two key dimensions of AI across our three-part global lens to develop a set of research questions for future marketing scholarship in this increasingly important domain.     

创新生态系统视角下价值共创如何影响企业创新绩效——一个有调节的中介模型

以创新生态系统为视角，引入创新资源互动与生态系统规范机制为中介变量和调节变量，探究价值共创如何影响企业创新绩效。基于307家企业样本数据，运用结构方程模型、Bootstrap和层级回归方法对数据进行分析。研究发现：创新生态系统中，价值共创不完全直接影响企业创新绩效；创新资源互动部分中介价值共创对企业创新绩效的影响；生态系统规范机制部分正向调节价值共创对创新资源互动的影响。最后提出，创新生态系统调控方与企业要差异化地制定提升创新绩效的实施方案，营造活跃的创新资源互动氛围，形成并完善系统内生态规范机制。     

邻近性与创新合作：最新研究进展

自邻近性理论提出以来，邻近性在创新合作网络及其演化中的作用得到了很多学者的关注，相关研究丰富而庞杂。从邻近性因素对创新合作的影响、邻近性因素在创新合作中的相互作用以及创新合作对邻近性因素的影响等方面梳理了当前的研究进展，力图在邻近性因素与创新合作构成的复杂系统中厘清相互关系与动态作用机制。在此基础上，针对当前研究中尚未明晰和解决的问题，进一步提出了未来研究中有待持续深入的议题。     

Introduction to symposium: Smallholders in communist and postcommunist societies

The primary contributions of smallholders during the communist and early postcommunist periods have been food production and labour for large farms. Those conditions are changing, however, as modern farms require less labour and food supply may be imported. For most smallholders in Central and Eastern European and former Soviet Union countries, the postcommunist neoliberal environment has not brought significant improvement, and strong arguments can be made that land grabbing, social and economic exclusion, and rural poverty are worse than regime bias during the communist period. Cooperatives, which have empowered smallholders in other parts of the world, have not been as well developed in postcommunist nations.     

External pressure or internal culture? An innovation diffusion theory account of small retail businesses’ social media use

COVID-19 put unprecedented external pressure on small businesses to adopt or increase use of social media while not all small businesses are internally ready for this rapid change. This study investigated the roles of external pressures and organizational culture of openness and learning in driving small retail business owners'/managers' social media use decisions by impacting their perceived usefulness and barriers, based on the innovation-decision process model from the diffusion of innovations theory and the theory of reasoned action. An online survey with structured measurements was administered to 411 U.S. small retail business owners/managers. Results from structural equation modeling revealed that external pressures positively influenced small business owners'/managers’ perceived usefulness and barriers and social media use intention. In addition, the culture of openness and learning positively influenced the perceived usefulness while mitigating the perceived barriers, thereby directly and indirectly influencing the social media use intention. Theoretical and managerial implications are discussed.